Motor vehicles, and in particular trucks, are a critical component of the system for transporting materials, goods, and people from place to place. The amount of energy required to move such vehicles depends on many factors. For instance, a substantial amount of energy is expended to overcome the resistance (drag) encountered in moving the vehicle through air. The amount of energy expended depends in large part on the aerodynamic drag force exerted on the vehicle by the air. By decreasing the aerodynamic drag force exerted on the vehicle, the operating cost of the vehicle can be significantly reduced. Thus, there exists a need for ways of reducing the aerodynamic drag force exerted upon the vehicle as the vehicle moves through an airstream. It has been discovered that the portions of an exhaust system which are disposed in the airstream result in a significant increase in the drag force exerted upon the vehicle. Thus, there exists a need for an exhaust system that is more aerodynamic over previously developed exhaust systems.